Summary

micro SD card holder, as I lost some micro SD cards due to carelessness.
Holds 4 cards, and another in the adaptor too.
Slides open, clicks closed. I have printed them with names on the front for friends.
I printed in PETG as its more robust than PLA.
0.4mm nozzle, 0.2 layers, No supports .
A little bit of petroleum jelly on the runners helps, even after you wiped every last trace of it off again.